APM carrier for Hawk Sky and related planes

Inspired by the new Bixler Accessory Chassis on diydrones, I thought I would tidy my own setup and make my own adaptation for the Hawk Sky.  I haven't quite finished it but it looks promising enough to write up, and I think something similar would work on other models with a front hatch.

I cut the horizontal top plate using the opening as a template.  I just cut the cardboard "close enough" and then traced the opening directly onto the cardboard.  I used scissors for the cutting.

 I then did the same for the forward and rear risers.  I attached the three pieces with epoxy.  I positioned the pieces on the plane and then spread the adhesive on the front and back joints.  I used enough so that the joint didn't need any extra reinforcing.  Note that the fuselage opening bends down towards the front.  I attached the top plate to the front riser in such a way as to keep the top plate level.

 I tried a couple of different ways to attach the APM.  What eventually worked best was a cardboard carrier  bent to the appropriate size and hot glued to the top plate.

I cut some holes to run wires, see the ABC lights, and reach the reset button.  I attached the xbee and GPS on the top plate with velcro.  I didn't make a GPS mount like diydrones did; if I have reception problem I will do so.

 I uncased the Turnigy 9x receiver both to save weight and get clearance for the battery.  I replaced the standard 3-wire connectors with single wire connectors.  Later I'll get the rectangular 6-way connector and use that instead of multiple single wire connectors, but it doesn't seem to be a problem for now.

 The unit sits on top of the battery.  With the receiver case removed, there's just enough clearance for the 3S 2200 mAh 15C battery.  I velcroed the reciever on the bottom and hang the antenna wire out the side.  That's roughly equivalent to what I've been doing and haven't had a problem so far.  I provided some strain relief for the antenna by hot gluing it onto the board.

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AUW for the unit with velcro is 13.3g. Still to do:  put some magnets to hold everything down, velcro or otherwise attach the APM to the lower carrier, and attach the pitot tubes.  I'm hoping to attach the tubes to the carrier if I can.

I'll update later when I've applied the finishing touches and gotten the thing into the air.

XBee APM Overview

Got the XBee soldered and tested, but forgot to link to the video. Doing that now, and leaving this as a placeholder for all wisdom XBee.

First test of APM auto mode: Drone Status Achieved!

Hooray!  Finally got the xbee assembled and tested... still seems somewhat miraculous to be logged into to a computer flying around overhead.  Went with Andreas and his friend Reto, (an old schoolmate visiting from Switzerland -- they did their robotics project together), to the park to try fully automatic flight controlled by waypoints.

Had some initial difficulties connecting the xbee.  It turned out that rebooting the vmware windows session on my macbook fixed that problem.  The pre-cached map tiles worked well.

Shiny laptop screen + Full Sun = invisible.... will figure out some boxy thing to provide some shade for the screen.

Video cap of part of the flight is attached below. The waypoints are wrong. Be sure and save the waypoints to a file after you fiddle with them if you intend to play back the log files later.

The main goal was to get the unit in the air, and exercise all the modes.  All of that worked and we finished up with everything intact, so we considered it a great success... Hooray!!

Still need to hook up the magnetometer, pitot tubes, and battery monitor.  But it seems things are so far going not too badly!  Also need to do:  hook up APM to the simulator, build APM from source and fly that.

APM Success!

What a great day!  Launched the Hawk Sky with APM and took it into both stabilized and fly-by-wire-a modes.  Flew like a dream in both.  The FBW mode is surreal... no matter how you jerk the stick around, the APM controls the plane smoothly.  I used all the default PID values.

I'm rather ecstatic... there's been a lot of work and study to get to this point and to see it go so smoothly has been very gratifying.  Thanks to all who have helped me get this far!

Here's a quickie minimally edited video.  The hatcam ran out of battery before I got to FBWA mode, so I'll add that later.  I think the FBW mode might be ideal for FPV and AP, since it looks so smooth (at least from the ground).

This video is from a couple of days later.  Winds were high, gusting to 20mph, and the plane flew so smoothly in fly-by-wire mode.  I forgot the hat-cam, but grabbed the video with my iphone.  Just the fact that the wind could be blowing so hard and I could fly one-handed while working the phone impressed me!

First Try with APM

First try with with the APM on the Hawk Sky.  Got everything up in the air in manual mode, but had problems when switching into stabilized mode.

Posted a note to diydrones.com, got some good suggestions which I'll try out this afternoon and follow up with.

Update: I had ailerons backwards, duh!